Hydroacoustic survey around Elephant Island (Subarea 48.1) and South Orkney Islands (Subarea 48.2), austral summer 2016

摘要

This paper submits the results of the acoustic cruise made in the austral summer of 2016. The survey delivers the bottom bathymetry, the geographic distribution of krill concentrations, and the presence of fish shoals in 1,500 nautical miles over the shelf and the continental slope (100-500 m), around Elephant Island and South Orkney Islands. Krill concentrations are described, as well as those of mackerel icefish (Champsocephalus gunnari), the latter representing the most abundant fish species in the research, besides other finfish species in the area. The mackerel iceflsh was found between 160 and 449 m depth, associated to steep bottom, showing demersal characteristics during the day and semi-pelagic overnight. During the darkness hours, the mean determined depth in the schools was 207.1 ± 62.6 m around Elephant Island and 219.4 ± 55.8 m in South Orkney Islands.